// Copyright (C) Kumo inc. and its affiliates.
// Author: Jeff.li lijippy@163.com
// All rights reserved.
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.
//
#pragma once

#include <pollux/expression/function_call_to_special_form.h>
#include <pollux/expression/special_form.h>

namespace kumo::pollux::exec {
    const char *const kCoalesce = "coalesce";

    class CoalesceExpr : public SpecialForm {
    public:
        CoalesceExpr(
            TypePtr type,
            std::vector<ExprPtr> &&inputs,
            bool inputsSupportFlatNoNullsFastPath);

        void evalSpecialForm(
            const SelectivityVector &rows,
            EvalCtx &context,
            VectorPtr &result) override;

    private:
        void computePropagatesNulls() override {
            propagatesNulls_ = false;
        }

        static TypePtr resolveType(const std::vector<TypePtr> &argTypes);

        friend class CoalesceCallToSpecialForm;
    };

    class CoalesceCallToSpecialForm : public FunctionCallToSpecialForm {
    public:
        TypePtr resolveType(const std::vector<TypePtr> &argTypes) override;

        ExprPtr constructSpecialForm(
            const TypePtr &type,
            std::vector<ExprPtr> &&compiledChildren,
            bool trackCpuUsage,
            const core::QueryConfig &config) override;
    };
} // namespace kumo::pollux::exec
